On deformation characterisation of machined surfaces and machining-induced white layers in a milled titanium alloy
On deformation characterisation of machined surfaces and machining-induced white layers in a milled titanium alloy
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DOI：
10.1016/j.jmatprotec.2021.117378
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发表时间：
2021-09-23
影响因子：
6.3
通讯作者：
Ghadbeigi, H.
中科院分区：
文献类型：
--
作者：
Brown, M.;M'Saoubi, R.;Ghadbeigi, H.
机加工引起的白色层和严重变形层是在机加工高强度航空航天合金时可能形成的不期望的表面完整性特征。设计并实施了正交铣削工艺，以评估切削速度、刀具磨损、切削刃半径和爬升与常规铣削相比对白色层形成和塑性应变分布的影响。在加工表面的塑性变形与形成的白色层在Ti-6Al-4V已被量化使用不同的长度尺度的微网格印刷使用电子束光刻技术。据发现，白色层形成通过严重的塑性变形机制，在等效塑性应变值超过1.2和区域的切削弧的瞬时切屑厚度小于切削刃半径和犁削和摩擦是占主导地位的机制。结果表明，在较低的切削速度下，在爬升铣削过程中，当加工具有较大的切削刃半径和刀具后刀面磨损时，测量的应变和塑性变形材料的深度的大小更大。
Machining-induced white layers and severely deformed layers are undesirable surface integrity features which can be formed when machining high-strength aerospace alloys. An orthogonal milling process has been designed and performed to assess the impact of cutting speeds, tool wear, cutting edge radius and climb vs conventional milling on white layer formation and plastic strain distribution. The plastic deformation in the machined surface associated with the formation of white layers in Ti-6Al-4V has been quantified using micro-grids of different length scales printed using the electron beam lithography technique. It was found that white layers formed via the severe plastic deformation mechanism, at equivalent plastic strain values in excess of 1.2 and in regions of the cutting arc with the instantaneous chip thickness of less than the cutting-edge radius and ploughing and rubbing being the dominant mechanisms. The results indicated that the magnitude of the measured strains and the depth of plastically deformed material was greater at lower cutting speeds, during climb milling and when machining with a larger cutting edge radius and tool flank wear land.